Induction of intrinsic and extrinsic apoptosis through oxidative stress in drug-resistant cancer by a newly synthesized Schiff base copper chelate

Multidrug resistance (MDR) in cancer represents a variety of strategies employed by tumor cells to evade the beneficial cytotoxic effects of structurally different anticancer drugs and thus confers impediments to the successful treatment of cancers. Efflux of drugs by MDR protein-1, functional P-glycoprotein and elevated level of reduced glutathione confer resistance to cell death or apoptosis and thus provide a possible therapeutic target for overcoming MDR in cancer. Previously, we reported that a Schiff base ligand, potassium-N-(2-hydroxy 3-methoxy-benzaldehyde)-alaninate (PHMBA) overcomes MDR in both in vivo and in vitro by targeting intrinsic apoptotic/necrotic pathway through induction of reactive oxygen species (ROS). The present study describes the synthesis and spectroscopic characterization of a copper chelate of Schiff base, viz., copper (II)-N-(2-hydroxy-3-methoxy-benzaldehyde)-alaninate (CuPHMBA) and the underlying mechanism of cell death induced by CuPHMBA in vitro. CuPHMBA kills both the drug-resistant and sensitive cell types irrespective of their drug resistance phenotype. The cell death induced by CuPHMBA follows apoptotic pathway and moreover, the cell death is associated with intrinsic mitochondrial and extrinsic receptor-mediated pathways. Oxidative stress plays a pivotal role in the process as proved by the fact that antioxidant enzyme; polyethylene glycol conjugated-catalase completely blocked CuPHMBA-induced ROS generation and abrogated cell death. To summarize, the present work provides a compelling rationale for the future clinical use of CuPHMBA, a redox active copper chelate in the treatment of cancer patients, irrespective of their drug-resistance status.     

Mitochondrial ROS generation for regulation of autophagic pathways in cancer

Mitochondria, the main source of reactive oxygen species (ROS), are required for cell survival; yet also orchestrate programmed cell death (PCD), referring to apoptosis and autophagy. Autophagy is an evolutionarily conserved lysosomal degradation process implicated in a wide range of pathological processes, most notably cancer. Accumulating evidence has recently revealed that mitochondria may generate massive ROS that play the essential role for autophagy regulation, and thus sealing the fate of cancer cell. In this review, we summarize mitochondrial function and ROS generation, and also highlight ROS-modulated core autophagic pathways involved in ATG4–ATG8/LC3, Beclin-1, p53, PTEN, PI3K–Akt–mTOR and MAPK signaling in cancer. Therefore, a better understanding of the intricate relationships between mitochondrial ROS and autophagy may ultimately allow cancer biologists to harness mitochondrial ROS-mediated autophagic pathways for cancer drug discovery.     

N-Nitrosopiperidine and N-Nitrosodibutylamine induce apoptosis in HepG2 cells via the caspase dependent pathway

The human hepatoma cell line (HepG2) exhibited a dose and time-dependent apoptotic response following treatment with N-Nitrosopiperidine (NPIP) and N-Nitrosodibutylamine (NDBA), two recognized human carcinogens. Our results showed a significant apoptotic cell death (95%) after 24 h treatment with NDBA (3.5 mM), whereas it was necessary to use high doses of NPIP (45 mM) to obtain a similar percentage of apoptotic cells (86%). In addition, both extrinsic (caspase-8) and intrinsic pathway (caspase-9) could be implicated in the N-Nitrosamines-induced apoptosis. This study also addresses the role of reactive oxygen species (ROS) as intermediates for apoptosis signaling. A significant increase in ROS levels was observed after NPIP treatment, whereas NDBA did not induce ROS. However, N-acetylcysteine (NAC) did not block NPIP-induced apoptosis. All these findings suggest that NPIP and NDBA induce apoptosis in HepG2 cells via a pathway that involves caspases but not ROS.     

Synergistic activation of JNK/SAPK induced by TNF-alpha and IFN-gamma: apoptosis of pancreatic beta-cells via the p53 and ROS pathway

IFN-γ and TNF-α are major proinflammatory cytokines implicated in islet β-cell destruction, which results in type-1 diabetes; however, the underlying mechanism is not clear. Using pancreatic β-cell line MIN6N8 cells, co-treatment with TNF-α and IFN-γ, but neither cytokine alone, synergistically induced apoptosis, correlated with the activation of the JNK/SAPK, which resulted in the production of reactive oxidative species (ROS) and loss of mitochondrial transmembrane potential (ΔΨm). Additionally, cells transfected with wild-type JNK1 became more susceptible to apoptosis induced by TNF-α/IFN-γ through ROS production and loss of Δψm, while cascading apoptotic events were prevented in dominant-negative JNK1-transfected or JNK inhibitor SP600125-treated cells. As the antioxidant, N-acetyl-cysteine, failed to completely suppress apoptosis induced by TNF-α/IFN-γ, an additional pathway was considered to be involved. The level of p53 was significantly increased through synergistic activation of JNK by TNF-α/IFN-γ. Furthermore, the synergistic effect of TNF-α/IFN-γ on apoptosis and ROS production was further potentiated by the overexpression of wild-type p53, but not with mutant p53. This synergistic activation of JNK/SAPK by TNF-α/IFN-γ was also induced in insulin-expressing pancreatic islet cells, and increased ROS production and p53 level, which was significantly inhibited by SP600125. Collectively, these data demonstrate that TNF-α/IFN-γ synergistically activates JNK/SAPK, playing an important role in promoting apoptosis of pancreatic β-cell via activation of p53 pathway together with ROS.     

Glutaredoxin 2 prevents H2O2-induced cell apoptosis by protecting complex I activity in the mitochondria

Glutaredoxin 2 (Grx2) belongs to the oxidoreductase family and is an isozyme of glutaredoxin 1 (Grx1) present in the mitochondria, however its function is not well understood. The purpose of this study is to evaluate the potential anti-apoptotic function of Grx2 by examining its ability to protect complex I in the mitochondrial electron transport system using human lens epithelial cells as a model. We found that cells treated with 200 μM hydrogen peroxide (H₂O₂) for 24 h exhibited decreased viability and became apoptotic with corresponding Bax up-regulation, Bcl-2 down-regulation, caspase 3 activation and mitochondrial cytochrome c leakage. Grx2 over-expression (OE) could protect cells against H₂O₂-induced damage while Grx2 knockdown (KD) showed the opposite effect. Under the same conditions, H₂O₂ treatment caused 50% inactivation of complex I activity in control cells (vector only), 75% in Grx2 KD cells but only 20% in Grx2 OE cells. Furthermore, the inactivated complex I in the H₂O₂-treated cells could be protected mostly by importing the purified nascent Grx2 protein, but not the Grx2 protein mutated at the active site with C70S, or C73S, or with C70S plus C73S. Immunoprecipitation study also revealed that Grx2 co-precipitated with complex I, but not complex II, in the mitochondrial lysate. Thus, the mechanism of Grx2 protection against H₂O₂-induced apoptosis is likely associated with its ability to preserve complex I.     

Inhibition of ROS production through mitochondria-targeted antioxidant and mitochondrial uncoupling increases post-thaw sperm viability in yellow catfish

Reactive oxygen species (ROS) are one of the main causes for decreased viability in cryopreserved sperm. Many studies have reported the beneficial effect of antioxidant supplements in freezing media for post-thaw sperm quality. In the present study, we explored two new approaches of ROS inhibition in sperm cryopreservation of yellow catfish, namely mitochondrial-targeted antioxidant and metabolic modulator targeting mitochondrial uncoupling pathways. Our study revealed that addition of MitoQ, a compound designed to deliver ubiquinone into mitochondria, significantly decreased ROS production, as well as lipid peroxidation, and increased post-thaw viability. Similarly, sperm incubated with 2,4-dinitrophenol (DNP), a chemical protonophore that induces mitochondrial uncoupling, also had reduced ROS production, as well as lipid peroxidation, and increased post-thaw sperm viability. Conversely, activation of uncoupling protein (UCP2) by 4-hydroxynonenal (HNE) neither reduced ROS production nor increased post-thaw sperm viability. Our findings indicate that ROS inhibition through mitochondrial-targeted antioxidant or mild mitochondrial uncoupling is beneficial for sperm cryopreservation in yellow catfish. Our study provides novel methods to mitigate oxidative stress induced damage in cryopreserved sperm for future applications.     

Oxidative stress by <Emphasis Type="Italic">Helicobacter pylori</Emphasis> causes apoptosis through mitochondrial pathway in gastric epithelial cells

Helicobacter pylori is a gram negative bacterium that infects the human stomach of approximately half of the world’s population. It produces oxidative stress, and mitochondria are one of the possible targets and the major intracellular source of free radicals. The present study was aimed at determining mitochondrial alterations in H. pylori-infected gastric epithelial cells and its relationship with oxidative stress, one of the recognized causes of apoptotic processes. Cells were treated with a strain of H. pylori for 24 h. Cellular oxidative burst, antioxidant defense analysis, mitochondrial alterations and apoptosis-related processes were measured. Our data provide evidence on how superoxide acts on mitochondria to initiate apoptotic pathways, with these changes occurring in the presence of mitochondrial depolarization and other morphological and functional changes. Treatment of infected cells with Vitamin E prevented increases in intracellular ROS and mitochondrial damage consistent with H. pylori inducing a mitochondrial ROS mediated programmed cell death pathway.     

Arsenic induced apoptosis in malignant melanoma cells is enhanced by menadione through ROS generation, p38 signaling and p53 activation

Introduction  Resistance to apoptosis is a prominent feature of melanoma. Pharmacological concentration of arsenic in combination with a widely known oxidant, menadione was explored in this study to synergistically sensitize malignant melanoma cells to apoptosis. The molecular mechanism of apoptosis and the signaling-pathways involved were thoroughly investigated. Materials methods and results  Menadione synergized NaAsO₂ to significantly increase ROS generation and facilitate the major apoptotic signaling events: alteration of mitochondrial membrane potential, cytochrome c release and anti-apoptotic protein Bcl-2 down-regulation and subsequent activation of caspase-9 and caspase-3 followed by poly-ADP-ribose polymerase-1 cleavage. Antioxidant N-acetyl-l-cysteine antagonized these events. Investigation of the signaling-pathway revealed significant suppression of AP-1 activity but not NF-κB upon NaAsO₂ and menadione application. An increase in p38 phosphorylation and p53 protein expression did also dictate the apoptotic response. Suppression of p38 activation with SB203580 and inhibition of p53 expression by siRNA attenuated apoptosis. Transfection of p53, in p53 null HCT cells augmented the apoptotic events. Moreover, the treatment also led to tumor size reduction in BALB/c mice developed by intra-dermal B16 mouse melanoma cell injection; however, it had no detectable pro-proliferative or pro-apoptotic effect on non-tumor keratinocytes, normal fibroblasts or PBMC. Conclusion  This study thus provides an insight into innovative mechanisms of melanoma sensitization, a proper cure against which is still elusive. Taken together, our data also provides the first evidence of arsenic activity accentuation by menadione through modulation of specific signaling-pathways.     

Inhibition of PI3K/AKT signaling via ROS regulation is involved in Rhein-induced apoptosis and enhancement of oxaliplatin sensitivity in pancreatic cancer cells

Several natural products have been demonstrated to both enhance the anti-tumor efficacy and alleviate the side effects of conventional chemotherapy drugs. Rhein, a main constituent of the Chinese herb rhubarb, has been shown to induce apoptosis in various cancer types. However, the exact pharmacological mechanisms controlling the influence of Rhein on chemotherapy drug effects in pancreatic cancer (PC) remain largely undefined. In this study, we found that Rhein inhibited the growth and proliferation of PC cells through G1 phase cell cycle arrest. Moreover, Rhein induced caspase-dependent mitochondrial apoptosis of PC cells through inactivation of the PI3K/AKT pathway. Combination treatment of Rhein and oxaliplatin synergistically enhanced apoptosis of PC cells through increased generation of intracellular reactive oxygen species (ROS) and inactivation of the PI3K/AKT pathway. Pre-treatment with the ROS scavenger N-acetyl-L-cysteine attenuated the combined treatment-induced apoptosis and restored the level of phosphorylated AKT, indicating that ROS is an upstream regulator of the PI3K/AKT pathway. The combination therapy also exhibited stronger anti-tumor effects compared with single drug treatments in vivo. Taken together, these data demonstrate that Rhein can induce apoptosis and enhance the oxaliplatin sensitivity of PC cells, suggesting that Rhein may be an effective strategy to overcome drug resistance in the chemotherapeutic treatment of PC.     

Plantainoside D protects adriamycin-induced apoptosis in H9c2 cardiac muscle cells via the inhibition of ROS generation and NF-kappaB activation

Plantainoside D (PD), was isolated from the leaves of Picrorhiza scrophulariiflora (Scrophulariaceae). The anti-oxidative activity of PD was evaluated based on scavenging effects on hydroxyl radicals and superoxide anion radicals. Adriamycin (ADR) is a potent anti-tumor drug known to cause severe cardiotoxicity. Although ADR generates free radicals, the role of free radicals in the development of cardiac toxicity has not been understood. This study was undertaken to investigate the protective effect of PD against ADR-induced apoptosis. In vitro, ADR caused dose-dependent toxicity in H9c2 cardiac muscle cells. Pre-treatment of the cardiac muscle cells with PD significantly reduced ADR-induced apoptosis of cardiac muscle cells. PD inhibited the ROS produced by ADR in the cardiac muscle cells. As well, PD increased GSH(glutathione), compared with ADR. In response to ADR, NF-kappaB was activated in H9c2 cells. However the treatment of PD reduced the activation of NF-kappaB. We also observed that the NF-kappaB inhibitor, PDTC, inhibited the cytotoxic effect on ADR-induced apoptosis in cardiac muscle cells. In parallel, IkappaBalpha-dominant negative plasmid-overexpression abrogated ADR-induced apoptosis in H9c2 cardiac muscle cells. In conclusion, these results suggest that Plantaionoside D can inhibit ADR-induced apoptosis in H9C2 cardiac muscle cells via inhibition of ROS generation and NF-kappaB activation. The pure compound PD can be a potential candidate agent which protects cardiotoxicity in ADR-exposed patients.     

Induction of apoptosis by Shikonin through ROS-mediated intrinsic and extrinsic apoptotic pathways in primary effusion lymphoma

Primary effusion lymphoma (PEL) is an incurable non-Hodgkin's lymphoma and novel biology-based treatments are urgently needed in clinical settings. Shikonin (SHK), a napthoquinone derivative, has been used for the treatment of solid tumors. Here, we report that SHK is an effective agent for the treatment of PEL. Treatment with SHK results in significant reduction of proliferation in PEL cells and their rapid apoptosis in vitro. SHK-induced apoptosis of PEL cells is accompanied by the generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential (Δψm), an activation of c-Jun-N-terminal kinase (JNK), p38, as well as caspase-3, -8, and -9. Scavenging of ROS in the presence of N-acetylcysteine (NAC) almost blocks the loss of mitochondrial membrane Δψm, activation of JNK, cleavage of caspase-3, -9, and an induction of apoptosis in SHK treated PEL cells. SP600125, a specific inhibitor of JNK, also rescues a proportion of cells from the apoptotic effect of SHK. In addition, inhibition of caspase activation in the presence of pan-caspase inhibitor, Q-VD-OPh, blocks the SHK-inducing apoptosis, but doesn't completely inhibit SHK-mediated JNK activation. Therefore, ROS is an upstream trigger of SHK-induced caspase dependent apoptosis of PEL cells through disruption of mitochondrial membrane Δψm in an intrinsic pathway and an activation of JNK in an extrinsic pathway. In a PEL xenografted mouse model, SHK treatment suppresses PEL-mediated ascites formation without showing any significant adverse toxicity. These results suggested that SHK could be a potent anti-tumor agent for the treatment of PEL.     

Vitamin E analogs trigger apoptosis in HER2/erbB2-overexpressing breast cancer cells by signaling via the mitochondrial pathway

Alpha-tocopheryl succinate (alpha-TOS) is a redox-silent vitamin E (VE) analog with high pro-apoptotic and anti-neoplastic activity. Here we investigated whether alpha-TOS and several novel VE analogs kill breast cancer cells over-expressing the anti-apoptotic receptor protein HER2/erbB2. The agents induced apoptosis at comparable levels in both erbB2-low and -high cells. Generation of reactive oxygen species (ROS) preceded mitochondrial destabilization and execution of apoptosis, as evidenced by the anti-apoptotic effects of exogenous superoxide dismutase and mitochondrially targeted coenzyme Q. Dissipation of DeltaPsi(m) was followed by cytochrome c and Smac/Diablo re-localization and caspase-dependent cleavage of death substrate. A resistance to apoptosis for the corresponding rho(0) counterparts confirmed a critical dependency for mitochondria during the induction of apoptosis in breast cancer cells mediated by VE analogs and linked apoptosis to generation of radicals as judged by the delayed accumulation of ROS in the cybrid cell types. We conclude that alpha-TOS causes efficient apoptosis in breast cancer cells independent of their erbB2 status. Since erbB2 is frequently over-expressed in breast cancers and renders the neoplastic disease resistant to established treatment, our findings are of clinical interest.     

Capsaicin induces apoptosis by generating reactive oxygen species and disrupting mitochondrial transmembrane potential in human colon cancer cell lines

Although genetic factors are a well-known cause of colorectal cancer, environmental factors contribute more to its development. Despite advances in the fields of surgery, radiotherapy and chemotherapy, the cure rates for colon cancer have not substantially improved over the past few decades. Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide), the principal pungent ingredient of hot chili pepper, has exhibited an anti-tumor effect in many cell types. However, the mechanisms responsible for the anti-tumor effect of capsaicin are not yet completely understood. In this study, we investigated whether capsaicin induces apoptosis in colon cancer cell lines. Capsaicin decreased cell viability in a dose-dependent manner in Colo320DM and LoVo cells. In addition, capsaicin produced cell morphology changes and DNA fragmentation, decreased the DNA contents, and induced phosphatidylserine translocation, which is a hallmark of apoptotic cell death. We showed that capsaicin-induced apoptosis is associated with an increase in ROS generation and a disruption of the mitochondrial transmenbrane potential. A possible mechanism of capsaicin-induced apoptosis is the activation of caspase 3, a major apoptosis-executing enzyme. Treatment with capsaicin induced a dramatic increase in caspase 3 activity, as assessed by the cleavage of Ac-DEVD-AMC, a fluorogenic substrate. In conclusion, our results clearly showed that capsaicin induced apoptosis in colon cancer cells. Although the actual mechanisms of capsaicin-induced apoptosis remain uncertain, it may be a beneficial agent for colon cancer treatment and chemoprevention.     

Ascorbate promotes the cellular accumulation of doxorubicin and reverses the multidrug resistance in breast cancer cells by inducing ROS-dependent ATP depletion

Chemotherapy is the most effective strategy for the treatment of metastatic breast cancer. However, P-glycoprotein (P-gp)-mediated multidrug resistance severely limits the efficacy of chemotherapy and is a major cause of the failure during chemotherapeutic treatment. In this study, we investigated the anticancer effects of combining chemotherapeutic drugs with ascorbate (AA) in human breast cancer cells. We found that combined administration of AA can improve the sensitivity of both MCF-7 and doxorubicin (Dox)-resistant MCF-7/Adr cells to Dox in vitro and in vivo by a reactive oxygen species (ROS)-dependent mechanism. Further studies proved that AA can promote the accumulation of Dox in MCF-7/Adr cells when combined with doxorubicin. AA had no effect on the expression of P-gp at the mRNA and protein levels, but could decrease its activity as demonstrated by an obvious inhibition of efflux of P-gp substrate Rh 123. AA reduced ATP levels in both MCF-7 and MCF-7/Adr cells, and pretreating AA-stimulating cells with catalase completely rescued ATP levels. With ATP reduction, we observed an increased cellular calcium and the appearance of vacuoles and micropores on the cell surface, indicating the increased cell membrane permeability in AA-treated MCF-7/Adr cells. The above results suggest that AA could promote the cellular accumulation of doxorubicin by inducing ROS-dependent ATP depletion. Clinically, a combination of AA with doxorubicin would be a novel strategy for reversal of the multidrug resistance in human breast cancer cells during chemotherapy.     

ROS accumulation contributes to abamectin‐induced apoptosis and autophagy via the inactivation of PI3K/AKT/mTOR pathway in TM3 Leydig cells

Abamectin (ABA) as one of the worldwide used compounds in agriculture has raised safety concerns on nontarget organism toxicity. However, the study of male reproductive system damage caused by ABA remains unclear. Our aim is to investigate the effect of ABA‐induced cytotoxicity in TM3 Leydig cells and their underlying mechanisms. ABA inhibits TM3 cell viability and proliferation via cell cycle arrested in the G0/G1 phase. In addition, ABA‐induced mitochondrial depolarization leads to an imbalance in Bcl‐2 family expression, causing caspase‐dependent apoptosis in TM3 cells. The increased ratio of cells expression LC3 protein and LC3‐II to LC3‐I indicated the activation of autophagy potentially. Further experiments revealed ABA treatment reduced phosphatidylinositol 3‐kinase (PI3K), protein kinase B (AKT) phosphorylation, and mammalian target of rapamycin (mTOR) phosphorylation. Pretreatment with a PI3K/AKT inhibitor, LY294002, mimicked the ABA‐mediated effects on cytotoxicity. Pretreatment with a PI3K/AKT agonist, insulin‐like growth factor‐1, reversed the effects of ABA. ABA caused the accumulation of intracellular reactive oxygen species (ROS) by increased intensity of the ROS indicator. However, N‐acetylcysteine as ROS scavengers inhibited ABA‐induced apoptosis and autophagy and reversed these ABA‐mediated effects on PI3K/AKT/mTOR pathway. On the basis of the above results, it is suggested that ABA exposure induces apoptosis and autophagy in TM3 cells by ROS accumulation to mediate PI3K/AKT/mTOR signaling pathway suppression.     

Mixed lineage kinase 3 connects reactive oxygen species to c-Jun NH2-terminal kinase-induced mitochondrial apoptosis in genipin-treated PC3 human prostate cancer cells

It has been reported that genipin, the aglycone of geniposide, induces apoptotic cell death in human hepatoma cells via a NADPH oxidase-reactive oxygen species (ROS)-c-Jun NH(2)-terminal kinase (JNK)-dependent activation of mitochondrial pathway. This continuing work aimed to define that mixed lineage kinase 3 (MLK3) is a key mediator, which connect between ROS and JNK in genipin-induced cell death signaling. In PC3 human prostate cancer cells, genipin stimulated MLK3 activity in concentration- and time-dependent manner. The PC3 cells stably transfected with dominant-negative form of MLK3 was less susceptible to population of the sub-G1 apoptotic cells, activation of caspase, collapse of mitochondrial membrane potential, and release of cytochrome c triggered by genipin, suggesting a crucial role of MLK3 in genipin signaling to apoptotic cell death. Diphenyleneiodonium (DPI), a specific inhibitor of NADPH oxidase, markedly inhibited ROS generation and MLK3 phosphorylation in the genipin-treated cells. Pretreatment with SP0600125, a specific inhibitor of JNK but neither U0126, a specific inhibitor of MEK1/2 nor PD169316, a specific inhibitor of p38 suppressed genipin-induced apoptotic cell death. Notably, both the phosphorylation of JNK and induction of c-Jun induced by genipin were markedly inhibited in PC3-EGFP-MLK3 (K144R) cells expressing a dominant-negative MLK3 mutant. Taken together, our observations suggest genipin signaling to apoptosis of PC3 cells is mediated via activation of ROS-dependent MLK3, which leads to downstream activation of JNK.     

Inhibition by epigallocatechin gallate of CoCl2-induced apoptosis in rat PC12 cells

Epigallocatechin-3-gallate (EGCG) is a major constituent of green tea polyphenols. This study was aimed to investigate the possible mechanisms of EGCG-mediated inhibition against apoptosis in rat pheochromocytoma PC12 cells by exposure to CoCl(2). Exposure to CoCl(2) caused the generation of ROS and induced cell death with appearance of apoptotic morphology and DNA fragmentation. However, EGCG rescued the loss of viability in the cells exposed to CoCl(2) and led the reduction of DNA fragmentation and sub-G(1) fraction of cell cycle. Also, EGCG attenuated the CoCl(2)-induced disruption of mitochondrial membrane potential (DeltaPsim), release of cytochrome c from the mitochondria to cytosol and abolished the CoCl(2)-stimulated activities of the caspase cascades, caspase-9 and caspase-3. In addition, EGCG ameliorated the increase in the Bax to Bcl-2 ratio, a marker of apoptosis proceeding, induced by CoCl(2) treatment. Taken together, the present results suggest that EGCG inhibit the CoCl(2)-induced apoptosis of PC12 cells through the mitochondria-mediated apoptosis pathway involved in modulating the Bcl-2 family.     

Combination therapy Eve and Pac to induce apoptosis in cervical cancer cells by targeting PI3K/AKT/mTOR pathways

This study aimed to investigate the anti-cervical cancer effects of everolimus (Eve) and paclitaxel (Pac) when used alone or in combination. Human cervical cancer cells HeLa and SiHa were divided into four group: Blank control group (control), everolimus group (Eve), paclitaxel group (Pac) and combined therapy group (Eve?+?Pac). The cell viability was detected by CCK-8 assay and the cell cloning ability was detected by clonegenic assay. Flow cytometry was used to detect cell apoptosis. Meanwhile, the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR) and their phosphorylated proteins were studied by western blot. The HeLa and SiHa cells proliferation and cloning ability were significantly inhibited in drug treatment groups compared with control group (p?相似文献   

绿木霉SM1蛋白诱导拟南芥防御反应以及激发活性氧途径研究

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